Welding apparatus



June 19, 1934. H. E. KENNEDY ET AL.

. WELDI-NG APPARATUS Filed Oct. 19, 1931 3 Sheets-Sheet 1 INVENTOR565447 Jan/"40%,, whet Q WW, BY 1% 3 m and a! J -ATT RN S BEE-BE I 319 1%k 27/ J1me 19, 1934.

H. E. KENNEDY ET AL WELDING APPARATUS Filed Oct. 19, 1931 3 Sheets-Sheet3 INVENTORS.

Patented June 19, 1934 WELDING APPARATUS Harry E. Kennedy, MaynardBerkeley,

Carbon Research Labora- Lloyd '1. Jones, Union Carbide and A. llotermnndand Calif., assignors to tories, Inc, a corporation of New YorkApplication October 19,

26Clnims.

1931, Serial No. 569,638 (Cl. 21H) This application is a continuation inpart of our arc and control circuit connected with the tool. copendingapplication entitled Method of maintaming a constant arc length inelectric welding",

filed October 22, 1930 and bearing Ser. No. 490,436.

The invention relates to electric welding and particularly pertains toan arc welding apparatus which includes an automatic control foradvancing the welding rod at substantially the rate of its consumptionand consequently maintaining an arc of a uniform length.

In our prior application we have pointed out that in electric weldingthe heat generated by the are forms a globule at the end of the weldingrod which rapidly increases in size and becomes unstable.

If the arc is of a proper length, the

globule is properly deposited on the work and during its depositionmomentarily bridges the gap between the welding rod and the work, shortcircuiting the arc. to we disclose a method In the application referredand apparatus utilizing the frequency of the metallic depositionsbetween the electrodes and their concomitant influence on an electricalcircuit for automatically regulating the arc length to maintain ituniformly short.

The present invention has for its principal object the provision of animproved efficient electric welding apparatus capable of maintaining anarc of a uniform length by automatically feeding the welding rod towardthe work at the rate of its consumption, this being accomplished byutilizing the influence of the frequency of metallic deposition betweenthe electrodes on an electrical control circuit.

In the preferred embodiment ofour invention which is herein disclosed wehave provided a hand tool for supporting the welding rod, which enablingit to be efficiently manipulated by an operator. The are circuit isconnected with the welding rod through the hand hand tool is fitted withing rod feeding device only during one portion of This feeding,mechanism control circuit is tool and to the work. The

an electromagnetic weldwhich advances the rod its cycle of operation. isinfluenced by a conarc circuit. This circuiting effect of the globularmovement between the electrodes to actuate the electromagnetic feedingdevice and advance the welding rod at the same rate as its consumption.

The invention is exemplified in the following description andillustrated in the accompanying dra Fig. 1 illustrates a welding centralsection and the Fig. 2 illustrates a modified form of hand tool forcarrying the welding rod.

-Fig. 3 diagrammatically illustrates the invention as embodied in a fuelautomatic welding apparatus.

In the drawings we have illustrated the welding rod feeding mechanism asembodied in a hand tool 10 of dimensions and weight enabling it to beconveniently and efficiently manipulated by an operator. The feedingmechanism, however, need not be embodied in an apparatus which isportable in the same sense as a hand tool. That is to say, we are mainlyconcerned with an electrically controlled device for accurately feedingthe rod in one direction at a rate of advance equalling the rate ofconsumption of the rod. We do, however, realize that a hand tool such asdisclosed has considerable merit and a wide field for use in connectionwith arc welding both in connection with our type of automatic controland others. Some of the novel features of the feeding device, however,may be employed without embodying them in a hand tool.

The hand tool 10 includes a cylindrical metallic body 11 having aprojecting handle 12 to which one conductor 14 of an arc welding circuitis connected. A coil 15 is wound about a hollow spool 16 arrangedcoaxially of the body 11 in a fixed position relative thereto. Mountedfor reciprocation at one end of the coil 15 is the armature 1'! of themagnet. This armature is formed with a conical cage 18 arrangedcoaxially of the spool 16. The tapered interior of this cage cooperateswith three balls 19 and a ball retainer 190; to form a one-way clutch.That is, the welding rod is projected axially through the cage 18 andspool 16 and when the armature is reciprocated the one-way clutchadvances the rod on alternate strokes but does not affect its positionon the opposite strokes. Thus, the rod is fed in one direction inincrements of advance. The length of the stroke of the armature andhence the increment of advance of the rod may be adjusted by alteringthe position of an adjusting nut 20 which acts to limit the movement ofthe armature away from the coil. The armature is moved in this directionby means of a spring 21 mounted concentrically within the spool 16.

The welding current from the conductor 14 is led to the welding rodthrough the handle 12, .the body 100 and thence through inner and outercones 22a and 22. The inner cone 22a is segmental and is in contact withthe welding rod. The conical surfaces of the inner and outer conescooperate to prevent retraction of the rod through the feeding device.That is, when the armature is attracted to the coil the ball clutchadvances the rod and the cones prevent retraction of the rod on thereturn stroke of the armature.

A spring pressed member 23 is provided to maintain the segments of theinner cone in contact with the rod and with the outer c6ne.

The electromagnetic feeding device just described is operated throughthe medium of a single phase impulse generator as will be hereinafterpointed out in connection withthe arc welding and control circuits.

We are aware, however, that the feeding mechanism may include say threesuch magnetic feeding devices engaging the same welding rod andoperating in' overlapping cycles being furnished with the proper energythrough the medium of a polyphase impulse generator 25a. Such anarrangement is illustrated in Fig. 2 and operation thereof will beapparent from the drawings and from the description of the operation ofthe device illustrated in Fig. 1.

In Fig. 2 of the drawings three one way clutches and the electromagneticactuating means areillustrated diagrammatically. As these clutches areconstructed and operated as illustrated in Fig. 1 of the drawings, thesame reference characters have been applied to the parts shown in Fig.2. The one way clutches are located one above another, as shown in Fig.2

and as explained in connection with Fig. 1, they operate to positivelyfeed the welding bar downwardly and they directly engage thewelding barin the downward feeding thereof.

We have disclosed our clutching mechanism .as being actuatedmagnetically. It is to be understood, however, that it is within thescope of the present invention to actuate such a one-way clutch foradvancing the welding rod through the medium of eccentrics or othersimilar or mechanical devices actuated by a motor or other electricalapparatus as illustrated Fig. 3. V

The one way clutch illustrated in Fig. 3 of the drawings is of the sameconstruction as the one way clutch shown in Fig. 1, as indicated by thesame reference characters being-applied to similar parts. Instead ofactuating the one way clutch electro-mechanically for a downward.feeding movement of the welding rod, however,

a rotary motor actuated eccen'tric 38 and oscillatory lever 39 areemployed. The lever 39 is fulcrumed at a point intermediate the endsthereof on an adjustable pivot 42 so as to form two arms 40 and 41, therelative lengths of which arms maybe varied by, adjusting the eccentricpivot 42. Theend of the arm 40 of the lever 39 rests upon the surface ofthe eccentric 38, and the end 44 of the arm 41 is provided with anaperture 43 through which the welding rod passes. As shown in Fig. 3,the end 44 of the arm 41 is at its lowermost position and bearingagainstthe upper end of the conical-shaped cap 18. In this position theforce applied by the arm 41 is acting against the tension of the. spring21 and the weldingrod has just been fed one'increment of advance towardthe work. When th'eeccentric 38 is'rotated one-half of a revoluagainstupward movement by the one way clutch. During the next half of arevolution of the ec- 'nected tothe conductor 14a.

centric 38, thearm 41 will force the cap 18 downward and the one wayclutch will be effective to move the welding rod another increment ofadvance toward the work. The distance of the increments of advance maybe varied by adjusting the eccentric pivot 42 by means of an operatingarm 45. It will thus be seen that either mechanical or electromechanicalmeans may be employed for feeding the welding rod toward the work. 1

For operating and controlling the welding rod carrying and feedingdevices previously described We provide electrical circuits such asillustrated in Fig. 1. The are circuit, of course, includes theconductor 14 connected to one terminal of an arc generator 24 which isled to the welding rod through the hand tool for supporting the weldingrod as previously described. This hand tool, as previously described, isfitted with a handle and we may prefer to lead the conductor through thehandle of the tool. The other terminal of the are 24 or that indicatedby the numeral 14a is led to the work.

A bipolar alternating current generator 25 is provided which is drivenat a contant speed in any preferred manner. We prefer that thisalternator 25 be driven at a speed of 1200 R. P. M. Under normaloperation forty impulses per second will be transmitted therefrom to thecoil 15 of the actuating electromagnet of the hand tool 10. Thealternatoris connected by a conductor 26 to the conductor 14 forelectrical connection to one terminal of the coil 15. The alternator isalso connected by a conductor 27 to the other terminal of the coil. Thislatter conductor in practice consists of a separate wire convenientlywoven ininterposed across the arc generator conductors l4 and 14a.

A control circuit is provided which includes a contactor 30, a condenser31 and a relay 32 of 'anysuitable type. One terminal of the contactor isconnected by a conductor 33 to the condenser 31 the latter being in turnconnected by a conductor 34 to one terminal of the coil 35 of the relay32. The other terminal of this coil is con- The contactor 30 isinterposed between the conductor 14 and the conductor 33 so that whenthe arc is struck, the contaotor 30 will close, electrically connectingthe conductor 33 to the conductor 14.

The capacity of the condenser 31 and the intain desirablecharacteristics to the impulses of current which pass the condenser.When-the voltage across the arc-is say twenty volts,-the condenser ischarged to a like potential. During the charging of the condenseracurrent willfiow through the coil 35 of the relay 32. When the arc isshort circuited by a metallic deposition between the welding rod and thework, the condenser is discharged through the arc and through the relaycoil 35. The constants of the condenser and the relay are such thatduring the charge or discharge of the condenser the current inthe coil35 of the relay causes the bar 36 of the relay to operate in the usualmanner, the bar 36 beingreturned to normal position through the medium I3 of a spring 3'7. The relay acts to close an auxiliary circuit whichshort circuits the resistance 29 to remove the same from the fieldcircuit of the alternator 25.

The constants of the condenser and the relay provide that the impulsesoperating the relay shall be of equal magnitude whether the are be longor short and whether the time of deposition of a metall c globulebetween the welding rod and work be long or short.

It is, of course, understood that the alternating current impulsesgenerated by the alternator 25 are sumcient to energize the coil of theelectromagnetic welding rod feed mechanism to attract the armature andadvance the rod when the resistance 29 is short circuited but when thisresistance 29 is part of the field circuit of the alternator 25, theimpulses thereof are insufficient to energize the coil sufficiently toattract the armature and advance the rod.

When the arc is short and the metallic depositions are frequent, thefield 28 of the alternator is sufiiciently weak, due to theinterposition of the resistance 29 into the field circuit of thealternator 25, that the coil of the magnetic feeding mechanism will notbe sufficiently energized to attract the armature and feed the weldingrod.

When the arc becomes long, the metallic depositions are fewer and theresistance 29 is shorted out more frequently through the medium of therelay 32. The impulses of the alternator 25 are then more frequentlystrong enough to advance the welding rod through the medium of theelectromagnetic feeding device of the hand tool.

The shortness of are or frequency of depositions to which the relay 32will respond may be adjusted by altering the tension of the spring 37.

In operation of the apparatus, welding wire is cut into lengths ofthirty-six or forth-eight inches which is about the length that may beconsumed before the operator of the welding apparatus desires to changehis position. This length of welding rod or wire is inserted through thehand tool 10 and the operator is then ready to strike his arc andproceed in the usual manner.

The current impulses from the alternator 25 will energize the coil 15and it willattract its armature. As this armature is fitted with aoneway clutch, reciprocation thereof will advance the welding rod towardthe work in increments of advance.

The moment the arc is struck, the control circuit, whichis in parallelwith the arc, will be electrically connected to the arc circuit throughthe contactor 30 so that the individual metallic depositions occurringin the arc may cause current impulses through the capacity 31 and thecoil 35 of the relay 32, and the operation of the relay through themedium of the resistance 29 influences the voltage of the alternator 25and consequently the operation of the electromagnetic feeding device ofthe hand tool. This infiuence is such that it tends to maintain an arcof a substantially constant length regardless of the rate of consumptionof the welding rod.

The increments of advance of the welding rod may be adjusted, of course,by altering the position of the adjusting nut 20 of the hand tool whichacts to limit the movement of the armature carrying the one-way clutchaway from the coil. Thus, by adjusting this nut 20 and the relay spring37, the amount and rate of advance of the welding rod may be regulatedso that an arc of substantially constant length may be maintained.

From the foregoing it is obvious that we have provided an arc weldingapparatus wherein an advancing medium is provided capable of advancingthe welding rod toward the work in increments of advance at a ratesubstantially equalling the rate of consumption of the rod so that asubstantially constant arc length may be maintained.

While we have disclosed preferred embodiments of our invention it is tobe understood that it may be embodied in various other forms withoutdeparting from our invention as deilned in the appended claims.

Having thus described our invention, what we claim and desire to secureby Letters Patent is:

1. A welding apparatus, an arc circuit therefor electrically connectedwith the work and the welding rod, said apparatus including anelectrically operated reciprocable welding rod advancing medium directlyengaging the welding rod and capable of advancing the rod toward thework on alternate strokes.

, 2. A welding apparatus, an arc circuit therefor electrically connectedwith the work and with the welding rod, said apparatus including anelectrically actuated welding rod feed mechanism provided withreciprocating means to directly engage the rod and advance the sametoward the work 'only during one portion of its cycle of operation andunaflecting the position of the rodduring the remainder of its cycle ofoperation,

and a circuit arranged in parallel with the are circuit to operate saidelectrically actuated feed mechanism for operating the latter.

3. A welding apparatus including a device for receiving and supporting awelding rod, and an electrically operated reciprocable medium includedin said device for directly engaging said welding rod and advancing thesame during one stroke of its cycle of operation.

4. A welding apparatus including a device for receiving and supporting awelding rod, an elecj 1 tromagnetically operated reciprocable weldingrod advancing medium incorporated in said device and directly engagingthe welding rod and capable when in operation of advancing the rod onalternate strokes and unafiecting the position 1.

of the rod on opposite strokes.

5., A welding apparatus including a device for receiving and supportingwelding rod, an electromagnetically operated reciprocable welding rodadvancing medium incorporated in said device and capable when inoperation of advancing the rod on alternate strokes and unaifecting theposition of the rod on opposite strokes, and

gripping means included in said device for gripping and holding the rodstationary during the ineffective strokes of saidadvancing medium.

6. A portable hand tool for a welding apparatus, said hand toolincluding an electrically controlled reciprocable welding rod advancingmedium directly engaging the welding rod and capable of advancing therod on alternate strokes and unaifecting the rod on opposite strokes.

7. A portable hand tool for receiving and supporting welding rod andthrough which the welding rod is projected, an electrically operatedwelding rod advancing medium incorporated in said' hand tool and capableof advancing the rod through said tool in increments of advance duringone portion of each cycle of its operation a and unaifecting theposition of the rod during the remaining portion of each cycle of itsoperation, and means incorporated in the hand tool effective to maintainthe rod stationary with respect to the hand tool during the ineifectiveportion of each cycle of operation of the advancing medium.

8. A portable hand tool for use in connection with welding apparatus,said hand tool comprising a body, a handle extending therefrom at rightangles to the axis of said body, said body being capable of enablingwelding rod to be projected coaxially therethrough, a one-way clutchmounted in the body for engaging the welding rod to advance the same inone direction during reciprocation of the clutch, means forreciprocating the clutch and means in the body for maintaining the rodstationary with respect to the body during the ineifectlve strokes ofsaid one-way clutch.

9. A welding apparatus, an arc circuit therefor to be connected with thework and with a welding rod, a mechanism for receiving and supportingthe welding rod, said mechanism includ ing an electrically operatedreciprocable welding rod advancing medium directly engaging the weldingrod and capable of advancing the rod toward the work on alternatestrokes and unaffecting the rod on .opposite strokes, and a circuitassociated with the arc circuit for actuating said welding rod advancingmedium.

10. A welding apparatus, an arc circuit therefor to be connected withthe work and with a welding rod a mechanism for receiving and supportingthe welding rod, said mechanism including an electrically operatedreciprocable welding rod advancing medium directly engaging the weldingrod and capable of advancing the rod toward the work on alternatestrokes and unaffecting the rod on opposite strokes, means'formaintaining said welding rod stationary relative to said mechanismduring the ineffective strokes of said advancing medium, and a controlcircuit arranged in parallel with the are circuit for controlling saidwelding rod advancing-medium.

11. A welding apparatus, a welding circuit therefor, said apparatusincluding a mechanism for receiving and supporting a welding rod, an

electrically actuated reciprocating rod feeding medium directly engagingthe welding rod and incorporated in said mechanism for engaging the rodand advancing the same during only one portion of its cycle of operationand unaffe'cting the position of the rod with respect to the mechanismduringthe remainder of its cycle of operation, gripping means includedin said mechanism for gripping the rod during the ineifective strokes ofsaid feeding medium to maintain the rod stationary relative to themechanism during the ineffective strokes of said rod feeding medium, andelectrical circuits arranged in parallel with the arc circuit foroperating the rod feeding medium and controlling the operation thereof.

12. A welding apparatus, an arc circuit therefor electrically connectedwith the work and with a welding rod,'sa.id welding apparatus includinga welding rod receiving and supporting mechanism, an'electromagnetically operated r'eciprocating welding rod advancingmedium directly engaging the welding rod-and incorporated in saidmechanism and capable of advancing the rod toward'the work on alternatestrokes and unaifecting the position of the rod on opposite strokes,means for imparting electrical impulses to'said electromagneticallyoperated medium for operating the same,-'and means controlled by thecharacteristic of the are for regulating said im-- pulses.

13. A welding; apparatus, an arc circuit therefor to be electricallyconnected withthe work and with a welding rod, said apparatus includinga mechanism for receiving and supporting welding rod relative to thework, said mechanism including an electrically operated welding rodfeeding device engaging the rod and advancing the same only during oneportion of its cycle of operation and unaffecting the rod during theremainder of its cycle of operation, an alternator ior deliveringelectrical current to said device for operating the same, and a controlcircuit influenced by the frequency of metallic depositions between thewelding rod and the work, said control circuit influencing the voltageof the alternator and consequently the operation of the feeding device.

14. In a welding apparatus, a reciprocable mechanism forengaging thewelding rod to advance the same in one direction on alternate strokesand unaifecting the position of the welding rod 'on opposite strokes,electromagnetic means for operating said device, an arc circuitelectrically connected with the welding rod and with the work, analternator connected with said electromagnetic means for energizing thesame,

a resistance in the field of said alternator, a conmechanism for feedingan electrode toward the work comprising means having only. a back andforth reciprocatory movement operative to-advance said electrode onevery alternate stroke, and means for moving said reciprocable means inopposite directions.

' 16. In welding apparatus, the combination of mechanism for feedin'g'anelectrode toward the work comprising means having only a back and forthreciprocatory movement operative to advance said electrode on alternatestrokes, and means for moving said reciprocable means in oppositedirections, said last-mentioned means including at least one electricaldevice for positively moving said reciprocable means in one of saiddirections. Y

17'. In welding apparatus, the combination of mechanism for feeding anelectrode toward the work comprising an electromagnet having anarmature, reciprocable means including said armature operative toadvance said: electrode on alternate strokes, and means for moving saidreciprocable means inopposite directions, said last mentioned meansincluding means for intermittently energizing and de-energizing saidelectro- 18; In welding apparatus, the combination of mechanism forfeeding an electrode toward the work comprising reciprocablemeansoperative' to advance said electrode on alternate strokes,

means for moving said reciprocable means in opposite direct-ionsincluding an electrical device associated therewith, and means forintermittently energizing and de-energizing said electrical devicesufliciently to move said reciprocable means in one of saiddirectionsand subsequently to permit movement thereof in the opposite direction.

- 19. In welding apparatus, the combination of mechanism for feeding anelectrode toward the work comprising an electromagnet having areciprocable armatureat oneend thereof provided with an aperture throughwhich said electrode extends, means including said reciprocable armatureoperative to advance said electrode on alternate strokes, and means formoving said reciprocable armature in opposite directions, said movingmeans including means for intermittently energizing and deenergizingsaid electromagnet sufficiently to attract said reciprocable armatureand move the same in one of said directions.

20. In welding apparatus, the combination of mechanism for feeding anelectrode toward the work comprising an electromagnet having a core anda reciprocable armature disposed at one end thereof provided with anaperture in alignment with the core, said electrode being adapted toextend through the core and the aperture, means including saidreciprocable armature cooperating with said electrode for effectingmovement thereof on alternate strokes, and means for moving saidreciprocable armature in opposite directi ns, said moving meansincluding means for inter nittently energizing and de-energizing saidelectromagnet sufliciently to attract said reciprocable armature andmove the same in one of said directions.

21. In welding apparatus, the combination of mechanism for feeding anelectrode toward the work comprising reciprocable means arranged toapply its force in line with the electrode being fed and operative toadvance the same on alternate strokes, and means for moving saidreciprocable means in opposite directions.

22. In welding apparatus, the combination of mechanism for feeding anelectrode toward the work comprising an electromagnet having anarmature, reciprocable means including said armature arranged to applyits force in line with the electrode being fed and operative to advancethe same on alternate strokes, and means including said electromagnetfor moving said reciprocable means in opposite directions.

23. In a welding system, the combination of a welding circuit includinga movable electrode and the work, mechanism for feeding an electrodetoward the work comprising reciprocable means arranged toapply its forcein line with the electrode being fed and operative to advance the sameon alternate strokes, and means for moving said reciprocable means inopposite directions, said moving means including an electrical deviceand a control circuit connected thereto and responsive to anelectricalcondition or said welding cir- 7 cuit for moving saidreciprocable means in at least one of said directions.

24. In a welding system, the combination of a welding circuit includinga movable electrode and the work, mechanism for feeding said electrodetoward the work comprising means having only a back and forthreciprocatory movement operative to advance said electrode on alternatestrokes, and means for moving said reciprocable means in oppositedirections, said moving means including at least one electrical device,and means including a control circuit connected to said electricaldevice and responsive to an electrical condition of said welding circuitfor positively moving said reciprocable means in at' least one of saiddirections.

25. In a welding system, the combination or a welding circuit includinga movable electrode and the work, mechanism for feeding said electrodetoward the work comprising an electromagnet having a reciprocablearmature at one end thereof provided with an aperture through which saidelectrode extends, means including said reciprocable armature operativeto advance said electrode on alternate strokes, and means for movingsaid reciprocable armature in opposite directions, said moving meansincluding a control circuit connected to said electromagnet andresponsive to an electrical condition of said welding circuit forintermittently energizing and de-energizing the latter sufliciently toattract said atmature and move the same in one of said directions.

26.- In a welding system, the combination of a welding circuit includinga movable electrode and the work, mechanism for feeding said electrodetoward the work comprising an electromagnet having a reciprocablearmature, means including said reciprocable armature cooperating withsaid electrode for advancing the latter on alternate strokes, means formoving said reciprocable armature in opposite directions, said movingmeans including .a control circuit connected to said electromagnet andresponsive to an electrical condition in said welding circuit forintermittently energizing and de-energizing said electromagnet'sufllciently to attract said armature and move the same in one of saiddirections.

HARRY E. KENNEDY. MAYNARD A. ROTER-MUND. LLOYD T. TONE.

